A conventional liquid sample heating vaporizer is, as illustrated in FIG. 6, provided with a vaporization tank having an inlet port for introducing a liquid sample and an outlet port for leading out a vaporized liquid sample, and heaters for heating and vaporizing the liquid sample retained in the vaporization tank. The heaters are provided outside a bottom wall and side walls, and configured to heat the liquid sample through the bottom and side walls. Temperature control of the liquid sample at the time of heating is performed by using temperature detection values from a liquid temperature sensor that detects a temperature of the liquid sample, and a heater temperature sensor provided for the heaters.
However, in the above configuration, surfaces that heat the liquid sample are an inside surface of the bottom wall and inside surfaces of the side walls, and because of heat transfer, in order for an inside surface temperature of the bottom wall or the like to become equal to a heater temperature, a time lag occurs. As a result, there exists a problem that the response property of the temperature control of the liquid sample is poor. Also, even in the case of performing the temperature control with use of the temperature detection values of the liquid temperature sensor and the heater temperature sensor, the temperature on the inside surface of the bottom wall or the like serving as a heating surface is unknown, and therefore it is difficult to perform the temperature control with high accuracy. In particular, in the case where a temperature enabling a required vapor pressure to be ensured, and a temperature (decomposition point) causing it to be thermally decomposed are close to each other, in the configuration in which the response property of the temperature control is poor, and highly accurate temperature control cannot be performed as described above, the liquid sample is thermally decomposed, and a problem becomes significant.
In addition, in order to solve a problem of a temperature reduction near a liquid surface, which is one of problems inherent in temperature control of a liquid sample, Patent literature 1 describes a vaporizing tank in which a cartridge heater is arranged near a liquid surface. The cartridge heater includes a heating wire and a tubular metallic containing body that contains the hearing wire, and is placed by being inserted inside from a side wall of the vaporizing tank.
In the above configuration, in order to perform temperature control of the cartridge heater, inside the metallic containing body of the cartridge heater, a temperature sensor that detects a temperature of the heating wire is provided. A temperature detection signal from the temperature sensor is obtained by a control part to thereby control electric power supplied to the heating wire of the cartridge heater.
However, heat from the heating wire is transferred to a liquid sample through the outside metallic containing body, and therefore a time lag occurs before the temperature of the heating wire and a temperature of the metallic containing body become equal to each other. If so, as described above, the control response property is poor, and controlling to a set temperature with high accuracy is also difficult.